Method and means for making metallic cartridge belt links



NOV- 4, 1941. H, A, LAYgTRoM 2,261,627

METHOD AND MEANS FOR MAKING METALLIC CARTRIDGE BELT LINKS Filed July 2,1941 4 Sheets-Sheet 1 Nov; 4, 1941.

METHOD AND MEANS FOR MAKING MET ALLIC H. A. LAYSTROM Filed July 2, 1941CARTRIDGE BELT LINKS 4 Sheets-Sheet 3 22 v 26 I .I F zi /4 um" O I iEVEUYUR & W

Nov. 4, 1 941.

H. LAYSTROM METHOD AND MEANS FOR MAKING METALLIC CARTRIDGE BELT LINKS IFiled July 2, 1941 4 Sheets-Sheet 4 Patented Nov. 4, 1941 METHOD ANDMEANS FOR MG METAL- LIC CARTRIDGE BELT LINKS Hilding A. Laystroln,Chicago, 111., assignor to Quality Hardware and Machine Corporation,

4 Claims.

Chicago, 111., a corporation of Illinois Application July 2, 1941,Serial No. 400,756

My invention relates to the manufacture oi! metallic cartridge beltlinks particularly of the type such asis shown in my Patent No.2,232,071, dated February 18, 1941, in which type of link axiallyaligned but spaced apart circular loops extend from one side of the linkbody for receiving a cartridge, and a circular hinge loop extends mm theother side of the body ior engagement between the cartridge supportingloops of an ad- Jacent link to receive the middle portion of thecartridge, so that the cartridges will form the link or hinge pins forthe successive links which build up the metallic belt.

In the link shown in my patent referred to, the cartridge supportingloop and the hinge loop are formed by progressive die operations intocircular form in the same direction from the link body. A stronger andmore desirable link will resuit by bending and forming the cartridgesupporting loops in one direction from the link body and by bending andforming of the hinge loop in the opposite direction from the body. Theobject of my invention is therefore to provide a method and means forsimultaneously forming the cartridge supporting loops in one directionand the hinge loop in the opposite direction. The sheet metal blank fora link is subjected to successive die operations in each 01' which thedie elements operate to simultaneously form the cartridge supportingloops and the hinge loop in opposite directions. The progressivei'ormation of a link may be by separate die sets, or by passage or thelink through the die fields of a unitary die structure, or some oi thelink formlngs may be by separate dies and other tormings by passagethrough a unitary or progressive die structure.

0n the drawings I have shown more or less diagrammaticaly a number ofdie sets for progressively forming the link in accordance with myimproved method. On these drawings:

Figure 1 is a plan view showing how the embryo links may be supportedfrom a sheet metal strip during travel of the strip through a unitarydie structure. in the manner-described in my Patent Nth 2, 32,071; 1 v

Figure 2 is a side view of the strip with the progressive linkformations thereon and with the progressive formation or the link beingsuch that in each forming ileld the cartridge supporting loops areformed downwardly and the hinge loops are simultaneously formedupwardly;

Figure 3 is a side elevation showing how the strip might be passedthrough a die structure for lm'mation oi the cartridge supporting loopsupbending of the metal for forming the cartridge supporting loops andthe hinge loop:

Figure 9 is a section on plane IX-IX of Figure 8;

Figure 10 is a section on plane XX of Figure 8; v i Figure 11 is a sideelevation'of cooperating die elements for continuing the .formation ofthe loops;

Figure 12 is a section on plane XIIXII of Figure 11;

Figure 13 is an under side view or the upper die element of Figure 11,looking from plane X1II- XIII:

Figure 14 is a plan view of the embryo link 1 formed by the die elementsof Figure 11;

Figure 15 shows the die sets and the final forming thereby of the linkloops. GnReferring to Figures 4 and 5, a link which may eflicientlymanufactured in accordance with my process, comprises the body 10 fromthe ends of which respectfully extend a circular loop II and the loop I!which are axially spaced apart, a loop I! extending from the edge of thebody Ill in a direction opposite to the loops II and II. The loop IIwill receive the bodyof a cartride, while the loop I 2 is contracted asshown to receive the contracted bullet end 01 a cartridge. The loop I3is engageable between the loops II and I! of an adjacent link in a chainto receive the middle portion of a cartridge so that the cartridges willform hinge pins for the successive links which build up the supportingbelt. In order to strengthen the hinge loop it against opening underbelt tension, the end oi. the loop is provided with a tongue against theinner side of the body Ill. The

loop ll extends from the upper edge at onev end of the body l0 andterminates at the lower edge ofthe body end, and the loop I! alsoextendsirom the upper edge of the other end of the body and terminatesat the lower edge of this end. the loops ii and I2 having thus beenformed by bending downwardly. The hinge loop ll which engages I3 extendsfrom the lower edge or the body It andterminates at the upper edgethereof where formed, and this stock may be in the form of a' steelband. The blank B for the link is cut from this stock, the legs fromwhich the loops II and- I2 are to be formed being flat and extending inone direction from the body III, and the leg from which the loop I3 isto be formed being also flat and extending in the opposite direction.With the cutting of the blank from the stock the central portion of thebody I3 is ofiset to one side of the plane of the legs II and I2 for thedesired distance between the axis of the loops II and I2 and the axis ofthe loop II in the finished link. The end of the leg 13 is alsodeflected to form the tongue I4. With the arrangement as shown inFigures 6 and 7, the center of the-body portion I3 i deflected upwardlyand the tongue forming end I4 is deflected downwardly so that in theflnished blank the tongue will engage the inner side or the deflectedbody part.

The blank B may be cut entirely out of the stock A and then subjected toprogressive die formation in separate die sets, or the blank may be cutfrom the stock strip entirely except for a small holding section, as forexample along the line I5, between the stock strip and the leg I3 closeto the base end of the leg, as shown on Figure 6. The stock strip withthe blank thus supported thereby along the line I! may then be passed'through a unitary die structure in a manner as explained in my PatentNo. 2,232,071,

the finished link being then removed from th stock strip by cuttingalong the line I5. This short holding line or neck I5 will not interferewith the formation into circular form of the legs I I, I2 and ll of theblank to form the link loops.

On Figures 8 to 15 a number of die setsare more or less diagrammaticallyshown which may be separate for successively receiving the link blankand embryo link forms, or which may be assembled into a unitary diestructure for progressive passage of the links therethrough whilsupported by a stock band.

Figures 8 to show a die assembly C com prising upper and lower elementsmovable toward and away from each other in any suitable manner. The linkblank B is inserted or ted between these die elements and after the dieoperation the link has the form as indicated by c. As best shown onFigures 9 and 10, the upper element of the die assembly C may comprisetwo bars I3 and I1 spaced apart at one end by a die member I3 whosewidth is equal to the axial width of the loop I 3 of the link and theaxial space between the loops II and I2 of the link. The die member I3is shaped to engage with and form the loop part I3 which is supported bya block I3 resiliently held up in the lower die element by the spring23. The separated bars oi the upper element of the die assembly areshaped at their lower edges to engage with the loop forming legs II andI! of the link to form them against a die block H in the lower elementof the die assembly. The die blocks I3 and 2| are so formed that whenthe die elements come together to partially iorm bend in the loop partl3 of the link. The die bars and 23.01 the upper die element are shapedto cooperate with the semi-cylindrical heads 21 a id 21' on the lowerdie element 24 for giving the link loop elements II and I2 asubstantially hali bend downwardly.

0n Figure 15, E indicates a die assembly for receiving the link form 11shown on Figure 11 and the loops, the body portion I3 of the links willr be substantially in a vertical plane.

0n Figures 11 to 14 is shown a die assembly for bending and deflectingthe loops into circular form, while F' indicates the die assembly iorbringing the tongue ll intimately against the inner side of the linkbody and to subject the loops to final pressure to bring the linkstotheir final form. ,When' the link formation after leaving the dieassembly 'D reaches the die assembly E, arbors 23 and 23 are projectedbetween the upper and lower die elements of the assembly E to receivethe partially bent loops II and I 2, and the loop I3, as it comes fromthe die'assembly D is shown in dotted lines and after operation of thedie assembly E the link has the form indicated by e.

The upper element of the die assembly E comprises die bars "and 3|spaced apart by a die tongue 32 depending from one end of the bars. Thedie tongue 32 has the inner inclined surface 33 leading to an uppersubstantially semicircular surface 34. When the upper anli lower dieelements or the die assembly E come together, the inclined upstandingloop forming part I3/oi the link form 11 is engaged by the inclinedsurface 33 and is swung toward the arbor 23, and. when the end of theloop part l3 reaches the semi-circular surface 34 as the two dieelements come together, the link part [3 is wrapped around the arbor 23and its tongue II is brought into place behind the link body III, aspring supported block 35,. receiving the bent lower part of the linkloop portion I3 in its semi-circular seat 33 so, that when the dieelements are brought togetherthe loop I3 is formed around the arbor 23.

The die block 33 is between and holds spaced apart two die plates 31 and"having V-shaped recesses 43 and II, respectively, whose bottoms aresubstantially semi-circular. The die bars 30v and 3| oi the upper dieelement have semi-circular recesses 32 and 33, respectively, therein inalignment with the recesses 43 and 4| in the lower die element. When theupper and lower die elements of the die assembly E are brought together,the depending loop forming legs II and I2 oi 'the link form d (dottedlines) encounter the outer inclined sides of the recesses 33 and 4| inthe die plates 31 and 33 and the loop forming parts II and I2 are thenswung around the arbor 23, and when their ends reach the inner inclinedsides of the recesses 43 and II these ends are deflected upwardly toengage around the arbor 23 and the recesses 42 and 43 of the upper dieelement engage the upper portions 01' the link form dso that as the dieelements flnally come together the link parts II and I2 will beintimately deflected around the arbor 23 to form the loops II and I2 ofthe link form c, this link form being almost in its final stage with theexception of the intimate deflection of the 2. The method of forming ametallic cartridge tongue ll into its final position behind the linkbody l0.

The deflection of the tongue Hand final forming oi. the link isaccomplished in the die assembly F in which spaced apart upper dieplates 44, and lower spaced apart die plates 45 received between themthe loops II and I! for final intimate deflection around the arbor 2B,and the upper and lower die plates 46 and 41,

' respectively, receive the loop l3 and engage the back of the tongue IIto force it firmly against the back of the link body III.

In some die operations, particularly where the link is formedprogressively through a unitary die structure while the link issupported from a stock strip, it maybe more practical and emcient toform the loops II and I2 upwardly and the loop l3 downwardly, as shownon Figure 3, instead of forming the loops II and I2 downwardly and theloop I3 upwardly as indicated on Figures 1 and 2. I

I have thus provided a very practical and efllcient method and means forforming metallic cartridge belt links either progressively by separatedie assemblies, or by a unitary die structure through, which the linksare progressively formed while being supported from a stock band, themain feature of the invention being the simultaneous formation of thelinks in opposite directions with each die operation.

I have shown a practical embodiment of die structures which could beused for the manufacture of the links in accordance with my method,

\ but I do not desire to be limited to the exact structure shown, aschanges and modifications may be made without departing from the scopeof the invention.

I claim as my invention:

1. The method of forming a metallic cartridge belt link of the typecomprising a supporting body with two axially aligned and spaced apartbelt link of the type comprising a body with axially aligned but spacedapart cartridge supporting loops on one side and a hinge loop on theopposite side for engagement between the cartridge supporting loops ofan adjacent link,

which consists in cutting the fiat link blank from and a circular hingesupporting loop on the other side opposite the spacing of the cartridgereceiving loops, which consists in passing the sheet metal blank for thelink through a series of die assemblies for progressive formation intothe finished link, and in each die assembly bending and forming the,twocartridge supporting loop portions in" one direction toward circularform and simultaneously bending and forming the hinge loop portion inthe opposite direction toward circular form.

4. The method 01' forming a metallic cartridge belt link of the typehaving a body with axially, aligned and spaced apartcartridge supportingloops on one side and a hinge loop on the other side in alignment withthe space between the cartridgesupporting loops, which consists incutting the link blank from a band of sheet metal but leaving a neck ofmetal between the band and blank for support of the blank duringformation thereof into the finished link, passing the blank through diestructure forsuccessive die operations thereon, and with each dieoperation bending and forming the cartridge supporting loop por ionstoward circular form in one direction from the supporting band andsimultaneously bending and forming the hinge loop portion towardcircular form in' the opposite direction from the supporting band, andthen cutting the flnishedlinkfrom the band at the supporting neck.

HIIDING A. LAYSTROM.

